Classification of DIN 51524 hydraulic oils

Hydraulic oils do not have uniform quality and viscosity classifications. Practically every manufacturer of hydraulic systems and equipment defines special requirements for oil. The most common standards are DIN and ISO VG (Viscosity Grade).

The most common are as follows:

• DIN 51524 HVLP – lubricants have additives that protect from corrosion, oxidation and wear, plus additives increasing their viscosity index (VI >140, pressure >100 bar). They are intended for universal application, however the biggest advantage is provided when used in external hydraulic systems.
• DIN 51524 HLP – lubricants have additives from corrosion, oxidation and wearing (VI >80-100, pressure >100bar). They are intended for universal application and they are recommended for use in internal hydraulic systems.
• DIN 51524 HL ‒ lubricants have additives protecting from corrosion and oxidation (VG >80-100, pressure >100bar). They are recommended for use in low pressure internal hydraulic systems.